This invention relates generally to the field of image processing and more particularly to the creation, enhancement transmission, and presentation of 3-dimensional (3-D) images on a 2-dimensional viewing surface.
Since the invention of the stereoscope in 1847, there has been a desire for emulating the 3-D images of nature instead of being content with two dimensional images which lack realism due to the absence of depth cues. Many techniques have been devised and developed for producing 3-D images, each varying in degree of success and quality of image. These techniques generally belong to two major classes, namely the autostereoscopic imaging class which is produces 3-D images which can be viewed freely without spectacles, and the binocular stereoscopic imaging class which produces 3-D images which requires observers to wear spectacles or viewers. Techniques of the later class have been found in 3-D movies of the 1950""s and in occasional 3-D image productions such as 3-D comic books.
Color separation of stereo images has been utilized for over fifty years in the production of photographs, 3D movies and the printed page. In prior art devices such as shown in U.S. Pat. No. 3,712,119, stereo images are separated by mutually extinguishing filters such as a blue-green lens filter over one eye and a red filter over the other eye. With this combination, a full true color image is not obtained, and this color combination may cause eye fatigue, and color suppression.
In the prior art an object of a single pure color matching the filter color e.g. red or blue-green, would be transmitted only to one eye and so would not appear in stereo. However, pure colors are rare, and most objects are off-white, or pastel shades and so contain all three primary colors. Thus, most objects will have some component of each color and this enables the separation of right and left stereo images.
Prints, drawings or representation that yield a 3-D image when viewed through appropriately colored lenses are called anaglyphs.
An anaglyph is a picture generally consisting of two distinctly colored, and preferably, complementary colored, prints or drawings. The complementary colors conventionally chosen for commercial printings of comic books and the like are orange and blue-green. Each of the complementary colored prints contains all elements of the picture. For example, if the picture consists of a car on a highway, then the anaglyph will be imprinted with an orange car and highway, and with a blue-green car and highway. For reasons explained below, some or all of the orange colored elements of the picture are horizontally shifted in varying amounts in the printing process relative to their corresponding blue-green elements.
An anaglyph is viewed through glasses or viewers having lenses tinted about the same colors used to prepare the anaglyph (hereinafter, xe2x80x9c3-D glassesxe2x80x9d). While orange and blue-green lenses are optimally used with an orange and blue-green anaglyph, red and blue lenses work satisfactorily in practice and apparently are conventionally used.
The orange elements in the picture are only seen through the blue lens, the red lens xe2x80x9cwashing outxe2x80x9d the orange elements. For the same reason, the green-blue elements are only seen through the red lens. Hence, each eye sees only one of the two colored pictures. But because the different colored elements are horizontally shifted in varying amounts, the viewer""s eyes must turn inward to properly view some elements, and turn outward to properly view others. Those elements for which the eyes turn inward, which is what the viewer does to observe a close object, are naturally perceived as close to the viewer. Elements for which the viewer""s eyes turn outward are correspondingly perceived as distant. Specifically, if the blue lens covers the viewer""s right eye, as is generally conventional, then any blue-green element shifted to the left of its corresponding orange element appears to the viewer as close. The element appears closer the greater the leftward shift. Conversely, as a green-blue element is shifted only slightly leftward, not at all, or even to the right of its corresponding red element, that element will appear increasingly more distant from the viewer.
In addition to horizontally shifting the element pairs relative to each other, some users of anaglyphy for comic books also vertically shift the element pairs a slight amount relative to each other. Those users believe that the slight vertical shift improves the 3-D effect.
Normally 3-D images appear monochromatic when viewed through 3-D glasses.
Three dimensional techniques are closely related to the psychology and physiology of an observer""s cognitive processes. Subtle changes in selection of portions of the spectrum presented to each eye can result in significant changes in the observer""s perception. Even when viewing the same 3-dimensional image through the same viewers, different observers may perceive a 3-dimensional image in different ways.
One problem common to most observers arises when viewing a pure red or pure blue region of a 3-dimensional image through red/blue 3-dimensional glasses. In such circumstances, one eye will perceive black and the other eye will perceive nothing. This has a psychological and/or physiological impact on the viewer which most viewers find disturbing.
Further, when observing 3-dimensional images in which the left and right images are captured using complementary filters, the images reproduced in the colors of the filters, and viewed through viewers of the same colors (e.g. red/blue glasses) which separate the images, 3-dimensional images appear only in black and white. That is, color information is lost in the preparation of the 3-dimensional image. This is characteristic of most 3-dimensional images.
When processing color images using computers, it is common to separate an image into (e.g.) red, green and blue image components. Commonly each color component is referred to as an image plane. In the display of color images on a color cathode ray tube it is common to apply information from each color image plane to a respective electron gun of the cathode ray tube.
Normally, in the past, when preparing 3-dimensional motion pictures, the anaglyph frames were prepared in the post production suite.
When color images are captured, it sometimes occurs that one of the colors utilized for representing the image may be overexposed or underexposed as reflected, inter alia, in an inadequate dynamic range for that color. That is, anytime the color appears at all, it appears at maximum value or anytime it appears it appears at some minimum value instead of being spread over the entire dynamic range of representation. This adversely affects the quality of 3-D image produced
The prior art generally required complex specialized equipment for the transmission of 3-dimensional images. This inhibited the use of 3-D technology because much capital investment has been devoted to equipment for handling regular 2-dimensional images. It would be desirable to utilize 2-dimensional transmission equipment to produce 3-dimensional images.
Accordingly, one advantage of the invention is the creation of 3-dimensional images which are perceived in color.
Another advantage of the invention is the elimination of the subjective disturbance perceived when either pure red or pure blue portions of an image are viewed.
Another advantage of the invention relates to correcting overexposure or underexposure of a particular color utilized in creation of 3-dimensional images.
Another advantage of the invention is the creation of 3-dimensional moving images on line rather than in the post production suite.
Another advantage of the invention is the transmission of 3-dimensional color television images over existing broadcast and communication facilities in a cost effective manner.
According to the invention, the foregoing and other objects and advantages are obtained by providing a device for making 3 dimensional color images which uses a left and a right color video camera, each of which produces synchronized outputs comprising 3 image planes with each plane corresponding to red, green and blue color information respectively. The red image plane from the left color video camera is combined with the green and blue image planes from the right color video camera to produce a three dimensional output signal. A frame grabber can be used for each color video camera to capture related frames of each color video camera to produce a still three dimensional digital anaglyph of the images captured by the frame grabber.
Another aspect of the invention involves a method for making three dimensional color images of a scene using a left and a right color video cameras and producing an output video signal from each camera having red, green and blue image planes and by providing green and blue image planes from the right color video camera and a red image plane from the left color video camera as the output signal.
Another aspect of the invention relates to apparatus for making three dimensional images using a left and a right video camera each producing an output comprising 3 image planes, each plane corresponding to particular color information. One image plane from one of the left or right video cameras, preferably the red image plane, is replaced with an image plane from the other of the left or right video cameras and the information from two cameras is combined into one or more three dimensional video images.
Another aspect of the invention relates to a method of creating a three dimensional image from two images captured from two different positions by resolving each of the two images into three separate color components and combining one color component from one of the two images with two color components from the other of the two images to create a combined image.
Still another aspect of the invention relates to a method of creating a three dimensional image from two digital images captured from two different positions by resolving each of the two images into separate color planes, and combining one color plane from one of the two images with at least one color planes from the other of the two images to create a combined three dimensional image.
A different aspect of the invention relates to a method and apparatus for making three dimensional images in which a left and a right color video camera each produce an output comprising red, green and blue image planes. Green and blue image planes from the right color video camera and the red image plane from the left color video camera are combined into an output signal. The color value of each pixel of the output signal is monitored and, when the value lacks a first threshold amount of blue or green color or lacks a second threshold amount of red or green color, a quantity of blue and/or green color or a quantity of red and/or green color, respectively, is added to the pixel color value. As a result, information from two color video cameras is combined into three dimensional color video images which are perceived more acceptably when observed through red/blue viewers.
Another aspect of the invention involves method and apparatus for making three dimensional images by using a left and a right color video camera to produce an output comprising red, green and blue image planes respectively. Green and blue image planes from the right color video camera and a red image plane from the left color video camera are combined as an output signal. The color values of each pixel of the output signal is monitored and, when the red value of a number of pixels indicates underexposure or overexposure in red, substituting a brightened value from the green image plane of the left color video camera. As a result, information from two color video cameras is combined into three dimensional color video images which are perceived more acceptably when viewed through red/blue viewers.
The invention also relates to a method and apparatus for broadcasting three dimensional television images by capturing images using a left and a right color television cameras. Each camera produces an output comprising red, green and blue image planes. A signal containing the output from the left color video camera is transmitted using a first television transmitter and a signal containing the output from the right color video camera is transmitted using a second television transmitter. At a receiver, signals from the first and second television transmitters are received and respective outputs comprising the three image planes from the left and right color video cameras, produced. Green and blue image planes from the right color video camera and a red image plane from the left color video camera are combined into an output signal for viewing on a display.
Another aspect of the invention related to a method and apparatus for broadcasting three dimensional television images by producing a color video output comprising red, green and blue image planes from left and a right color video cameras; broadcasting signals containing the output from the right color video camera using a television transmitter; transmitting signals containing the red image plane from the left color video camera over a point to point communications link; and receiving at a receiver the signals from the television transmitter and said signals from the point to point communications link for providing green and blue image planes from the right color video camera and a red image plane from the left color video camera as an output signal to a display for viewing. Thus, information from two color video cameras is combined into three dimensional color video images at a receiver.
Another aspect of the invention includes the computer generation of 3-dimensional anaglyphs. An object is represented in a 3-dimensional representation such as a wire frame generated using a 3-dimensional database. A full color surface can be rendered (applied) on the wire frame. Two different 2-dimensional views of the object are generated from different perspectives, corresponding, in one example, to views from the left and right eyes. The red image plane from the left perspective is combined with the blue-green image planes from the right perspective to create a 3-dimensional anaglyph representation of the object.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.